While addressing the media at the Westpac Centre on Wednesday afternoon, Buckley said that O'Brien's availability for Saturday's game against Greater Western Sydney will be "addressed this afternoon" when the match committee selects its squad of 25.
According to Buckley, O'Brien trained well on Wednesday morning and as such remains a chance to play his first match since round 14.
In other selection news, Buckley said that ruckman Darren Jolly has "probably come on ahead of schedule" in his rehabilitation from knee surgery, but is not in the mix to play against the Giants this week.
Junior ruckman Brodie Grundy "could" play this week, as his VFL form has been "excellent", while the veteran Ben Hudson "is a chance to get up. He will be managed through the week. He has been fantastic for us...if he's available, he'll play."
Injured star Dale Thomas has been toiling away in the gym for some time as he recovers from ankle surgery and his hard work hasn't gone unnoticed by the senior coach.
Thomas has gone on record as saying that he is aiming to make his return by round 20 and Buckley didn't say anything to dampen his hopes.
"He ran about 8ks out on the track wearing a brace," Buckley said.
"His progress at the moment has been very encouraging. We couldn't be more impressed with his attitude and the way he's gone about it."
When discussing last week's loss to Gold Coast, Buckley admitted that he and his coaches had made what was "clearly a mistake" in not applying a tag to Suns champion Gary Ablett who ran riot with 49 possessions.
Buckley said that the coaches had taken into consideration the fact that Ablett had helped himself to 53 possessions but was unable to prevent Gold Coast from losing by 97-points to the Magpies last year, although he conceded that Gold Coast's squad is "lifting around him".
On Collingwood's inaccuracy in front of goal, and in particular that of Travis Cloke (who has kicked 4.9 in his past two games), Buckley said that Cloke puts "a power of work in" and labelled him a "workaholic".
"He was kicking really well three or four weeks ago but has kicked 4.9 recently. Execution cost us on this occasion and it's one area we need to get right."
